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reducing dependencies on simplifier

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2017-08-22 15:09:34 -07:00
parent a206362cef
commit e2b46257d6
18 changed files with 289 additions and 215 deletions
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2
src/ast/rewriter/arith_rewriter.h
View file

@ -35,7 +35,6 @@ protected:
bool is_numeral(expr * n) const { return m_util.is_numeral(n); }
bool is_numeral(expr * n, numeral & r) const { return m_util.is_numeral(n, r); }
bool is_zero(expr * n) const { return m_util.is_zero(n); }
bool is_minus_one(expr * n) const { return m_util.is_minus_one(n); }
void normalize(numeral & c, sort * s) {}
app * mk_numeral(numeral const & r, sort * s) { return m_util.mk_numeral(r, s); }
@ -45,6 +44,7 @@ protected:
decl_kind power_decl_kind() const { return OP_POWER; }
public:
arith_rewriter_core(ast_manager & m):m_util(m) {}
bool is_zero(expr * n) const { return m_util.is_zero(n); }
};
class arith_rewriter : public poly_rewriter<arith_rewriter_core> {

4
src/ast/rewriter/poly_rewriter.h
View file

@ -39,7 +39,6 @@ protected:
bool is_numeral(expr * n) const { return Config::is_numeral(n); }
bool is_numeral(expr * n, numeral & r) const { return Config::is_numeral(n, r); }
bool is_zero(expr * n) const { return Config::is_zero(n); }
bool is_minus_one(expr * n) const { return Config::is_minus_one(n); }
void normalize(numeral & c) { Config::normalize(c, m_curr_sort); }
app * mk_numeral(numeral const & r) { return Config::mk_numeral(r, m_curr_sort); }
@ -111,6 +110,9 @@ public:
bool is_mul(expr * n) const { return is_app_of(n, get_fid(), mul_decl_kind()); }
bool is_add(func_decl * f) const { return is_decl_of(f, get_fid(), add_decl_kind()); }
bool is_mul(func_decl * f) const { return is_decl_of(f, get_fid(), mul_decl_kind()); }
bool is_times_minus_one(expr * n, expr*& r) const;
bool is_var_plus_ground(expr * n, bool & inv, var * & v, expr_ref & t);
br_status mk_mul_core(unsigned num_args, expr * const * args, expr_ref & result) {
SASSERT(num_args > 0);

60
src/ast/rewriter/poly_rewriter_def.h
View file

@ -931,3 +931,63 @@ expr* poly_rewriter<Config>::merge_muls(expr* x, expr* y) {
m1[k] = mk_add_app(2, args);
return mk_mul_app(k+1, m1.c_ptr());
}
template<typename Config>
bool poly_rewriter<Config>::is_times_minus_one(expr * n, expr* & r) const {
if (is_mul(n) && to_app(n)->get_num_args() == 2 && is_minus_one(to_app(n)->get_arg(0))) {
r = to_app(n)->get_arg(1);
return true;
}
return false;
}
/**
\brief Return true if n is can be put into the form (+ v t) or (+ (- v) t)
\c inv = true will contain true if (- v) is found, and false otherwise.
*/
template<typename Config>
bool poly_rewriter<Config>::is_var_plus_ground(expr * n, bool & inv, var * & v, expr_ref & t) {
if (!is_add(n) || is_ground(n))
return false;
ptr_buffer<expr> args;
v = 0;
expr * curr = to_app(n);
bool stop = false;
inv = false;
while (!stop) {
expr * arg;
expr * neg_arg;
if (is_add(curr)) {
arg = to_app(curr)->get_arg(0);
curr = to_app(curr)->get_arg(1);
}
else {
arg = curr;
stop = true;
}
if (is_ground(arg)) {
TRACE("model_checker_bug", tout << "pushing:\n" << mk_pp(arg, m()) << "\n";);
args.push_back(arg);
}
else if (is_var(arg)) {
if (v != 0)
return false; // already found variable
v = to_var(arg);
}
else if (is_times_minus_one(arg, neg_arg) && is_var(neg_arg)) {
if (v != 0)
return false; // already found variable
v = to_var(neg_arg);
inv = true;
}
else {
return false; // non ground term.
}
}
if (v == 0)
return false; // did not find variable
SASSERT(!args.empty());
mk_add(args.size(), args.c_ptr(), t);
return true;
}